Naomie Ackie, who stars as Whitney Houston in the upcoming biopic “I Wanna Dance With Somebody”, was dealt with a “fascinating” technical challenge while working on the film.

The English actress steps into the legendary singer’s shoes from her teenage years up until her death at age 48. Early on, Ackie and the filmmakers decided not to use prosthetics or CGI ageing for her performance because “it felt a little heavy handed.”

READ MORE: ‘I Wanna Dance With Somebody’ Trailer Sees Naomi Ackie Bring Out Whitney Houston’s Strength

“It was quite interesting,” Ackie told ET Canada. “It was the big marker that I had to work on because hair and costume beautifully were arranged by the people we had. But for me, it was about vocal tone.”

The 30-year-old star noted that there is a big difference “if you jump from the interviews Whitney did at 19 to some of the interviews, she did say at, 45.”

“You know, naturally you age,” Ackie explained. “But also there is like a kind of a raspiness to her voice that I wanted to try and achieve.”

READ MORE: Stanley Tucci Reveals Naomi Ackie’s Performance In Upcoming Whitney Houston Biopic Is ‘Extraordinary’

“We got an understanding that she’s aging, but also [that] there may be some vocal damage that’s happening because of how much she’s working, but also because of her lifestyle,” she continued.

While the actress admits “it was a challenge,” she says it “was really fascinating and something I wanted to achieve technically to allow the audience to suspend their disbelief for the duration of the film.”

“I Wanna Dance With Somebody” hits theatres on Dec. 23.